This invention relates generally to filtering a biological liquid. More specifically, this invention comprises an automatic gravity driven in-line filtration system and method for filtering a biological liquid such as blood or blood product to remove leukocytes therefrom.
Various blood filtration systems exist in the prior art. However, of the systems that are in-line filtration systems, these require user manipulation of valves and/or mechanically driven components during the filtration process. The manipulation of valves must take place at the proper time during the filtration process or the system will not filter properly and the blood being filtered may be rendered unusable. The use of mechanically driven components requires additional utility hook ups and complicates the overall system. Since systems including user manipulation of valves and mechanically driven components are more time dependent, use restrictive and costly, it is desirable to achieve a liquid filtration system which may filter blood without the manipulation of valves or the use of mechanically driven components.
Additionally, it is desirable to obtain a system wherein an additive storage solution is located remotely from a whole blood collection container. As will be described in greater detail hereinafter, the features of the present invention differs from those previously proposed.
The shortcomings of the prior art may be alleviated using a filtration system constructed in accordance with the principles of the present invention. The present invention comprises a process for filtering a biological liquid in an in-line filtration system. The process may comprise the following steps: providing the biological liquid in a collection container; conveying an additive solution into the collection container to nix with the biological liquid wherein the additive solution is located in a storage container and is automatically restricted to flow in a fluid path substantially bypassing a filtration media, the filtration media being disposed between the collection container and the storage container; mixing the biological liquid and the additive solution to form a mixture; and conveying the mixture into the storage container wherein the mixture is automatically restricted to flow in a second fluid path substantially passing through the filtration media.
According to the present invention there is also provided an in-line biological liquid filtration system. The system preferably comprises the following. A collection container for receiving biological liquid. A filter located downstream of the collection container and in fluid flow communication therewith. A storage container for receiving filtered biological liquid located downstream of the filter, the storage container in fluid flow communication with the filter and with the collection container. An additive solution located in the storage container. And, at least one automatic control member automatically restricting a flow of biological liquid or additive solution between the collection container and the storage container.
Another feature of the invention relates to a process and system for providing a collection container that is substantially free of any additive solution before and while biological liquid is collected in the container. Further, the additive solution is preferably located remotely in another container that serves as both a storage container for the additive solution prior to using the system and then as a long term storage container for biological liquid, preferably comprising blood or blood product, after the liquid is filtered through the system.
Still other features of the invention concerns the use of multiple storage containers and processes for separating and filtering the biological liquid, means for sampling collected liquid and an automatic, gravity operated, closed in-line filtration system.
In accordance with the following, it is an advantage of the present invention to provide an easy to use, closed in-line filtration system that can operate automatically merely under the force of gravity with minimum user supervision and without mechanical component manipulation.
A further advantage is to provide an invention that can be used with conventional liquid separation techniques, such as a centrifuge, without breaching the integrity of the closed system and while enabling multiple separation steps and storage containers for blood and blood products.